The present invention is directed to a motor vehicle door, and more particularly, to a motor vehicle door having a door body separated into a wet area and a dry area by a hermetic separator.
The term xe2x80x9cdry area of a motor vehicle doorxe2x80x9d here means that region of the motor vehicle door which bounds the vehicle interior (passenger compartment) or forms of boundary between a door lining and the wet/dry area separator.
Motor vehicle doors which have no wet/dry area separator or only a low-quality (e.g., foil type) wet/dry area separator are equipped with electrical aggregates and electrical plug connections exclusively in so-called wet area design, which results in higher costs in comparison with the dry area design. Moreover, the passage of moisture and dust into the passenger compartment results in a degradation of the compartment climate.
In contrast, in the case of motor vehicle doors with a virtually hermetic wet/dry area separator, the passage of moisture and dust into the passenger compartment is prevented such that the compartment climate is not impaired, and all electrical as well as electronic components can be constructed in dry area design. On the other hand, a comparatively high level of water can develop in the wet area of the motor vehicle door during rain and relatively fast driving because of the underpressure which develops there. This underpressure prevents the water from being able to drain out through the openings in the bottom of the door unobstructed. With an increasing level of water, the requirements on the seals in the flooded region increase. Moreover, at high speeds very high turbulence develops in the wet area of the motor vehicle door, which distributes fine water droplets in the entire wet area such that an opening in the wet/dry area separator even for the purpose of pressure equalization would result in an unacceptable degradation of the dry area conditions if it were arranged in the window parapet area.
A motor vehicle of the type described is disclosed in DE 196 22 310 A1.
It is thus an object of the invention to guarantee high-quality wet/dry area separation, and at the same time, achieve an effective lowering of the inherent anticipated maximum water level.
The present invention is directed to a motor vehicle door having a door body separated into a wet area and a dry area by a separator. Accordingly, the element constituting the wet/dry area separator of the motor vehicle door, in particular the door lining and/or a corresponding separator element, has at least one air-permeable pressure equalization element. This may be integrated directly into the wet/dry area separator, i.e., be a component of the wet/dry area separator. It is possible that the wet/dry area separator as a whole be designed as a pressure equalization element.
The pressure equalization element is air-permeable from the side of the dry area in the direction of the wet area and water and dust-impermeable in the opposite direction (from the wet-area side in the direction of the dry area). To this end, the wet-area side of the pressure equalization element has the least possible affinity for water and dust. In preferred embodiments, the pressure equalization element comprises fabrics made of hydrophobic fibers. In alternative embodiments, other fabrics which are provided on the wet-area side with a coating of the hydrophobic substance could also be used. Moreover, the pressure equalization element may also be formed from a gas-permeable diaphragm preferably made of a hydrophobic substance.
Of course, to ensure the function desired, care must be taken that an adequately large volume of airflow can flow from the passenger compartment into the dry area. This may occur through the edge region of the door lining or through passages provided especially for this at other locations, whereby these passages can preferably be covered with an air-permeable coating having a low water resistance.
In order to always be able to be effectively use the entire surface of the pressure equalization element, this should be positioned as much as possible completely above an assumed maximum standing water line. The decrease in pressure obtainable is greater the higher the volume of airflow through the pressure equalization element. Consequently, the pressure equalization element should form as large a share as possible of the wet/dry area separator. An increase in capacity can also be achieved by lowering the specific pressure loss of the pressure equalization element.
A preferred embodiment of the invention provides that the pressure equalization component is a functional unit installable in an opening of the door lining or in the separation element. It seems particularly advantageous to use a speaker diaphragm based on a substance with the properties described. Thus, the technical objective can be achieved without any added expense.
According to a second embodiment, the pressure equalization element constitutes a part of a housing of a functional unit, such as a gear housing, an airbag housing, or even a closing element of an assembly opening. The integration of the pressure equalization element into functional units which, can be preassembled and tested outside the motor vehicle door, ensures comparatively simple and reliable producibility and handleability.
Another embodiment of the invention provides for integrating the pressure equalization element into the door lining, whereby an opening between the wet area and the dry area is closed by the installation of the door lining on the vehicle door. To this end, the pressure equalization element and the opening in the wet/dry area separator should be surrounded by an intermediate elastic seal. If the material of the pressure equalization element is suitable for use for design elements, e.g., based on a fabric coated on one side, the entire door lining or parts thereof can be coated with the special fabric. A larger number of small perforations in the basic body of the door lining or a porous basic body inner lining with pores open all the way through guarantees the passage of air.
According to an another alternative embodiment, the pressure equalization element may also be a component of a foam sheet, which is preferably pressed from the dry-area side onto the entire surface of a mechanical support (e.g., door lining or support plate of a door module) provided as a sealing element and thus forms the actual wet/dry area separator. In this case, an opening for the pressure equalization element is arranged in the mechanical support.
The pressure equalization element may also serve to exhaust the gases contained in the airbag after deployment of an airbag. Moreover, based on the venting capability provided by the pressure equalization element, pressure is equalized between the vehicle door and vehicle interior and the closing of the motor vehicle door is facilitated. This makes separate ventilation openings for this purpose unnecessary.